CN212028325U

CN212028325U - Sliding bearing assembly with radial centralizing and axial thrust functions

Info

Publication number: CN212028325U
Application number: CN202020509209.1U
Authority: CN
Inventors: 谭春飞
Original assignee: China University of Petroleum Beijing
Current assignee: China University of Petroleum Beijing
Priority date: 2020-04-09
Filing date: 2020-04-09
Publication date: 2020-11-27
Anticipated expiration: 2030-04-09

Abstract

The utility model provides a have radial righting and axial thrust effect's slide bearing assembly concurrently, include: the static ring comprises a static ring base body, wherein the static ring base body is provided with a first inner cylindrical surface provided with a first radial friction part along the radial direction and is provided with a first thrust surface and a second thrust surface which are opposite along the axial direction; at least one of the first thrust surface and the second thrust surface is provided with a first axial friction part; the radial moving ring comprises a radial moving ring base body, the radial moving ring base body is provided with a second outer cylindrical surface provided with a second radial friction part along the radial direction, and the first radial friction part and the second radial friction part form a radial friction pair; the axial rotating ring comprises an axial rotating ring base body, the axial rotating ring base body is provided with a third thrust surface provided with a second axial friction part along the axial direction, and the first axial friction part and the second axial friction part form an axial friction pair. The utility model discloses be applied to among the oil gas drilling downhole tool, have longer life, and with low costs, the reliability is high.

Description

Sliding bearing assembly with radial centralizing and axial thrust functions

Technical Field

The utility model relates to a drilling equipment technical field especially relates to a have the slide bearing assembly of radial righting and axial thrust effect concurrently, is applicable to drilling downhole tool, instrument.

Background

Downhole tools for oil and gas drilling, in particular turbo drilling tools, helical drilling tools, rotary steerable, vertical drilling systems, downhole generators and the like, are usually elongated rods with small radial dimensions and high ambient temperature and pressure. The entry of small particles (e.g., debris, silica sand, etc.) from the drilling fluid into the radial centralizing bearings and axial thrust bearings of these devices can easily cause rapid wear of the bearings and premature failure. The radial centralizing bearing and the axial thrust bearing are important parts in a downhole tool and are also vulnerable parts (the bearings in the prior art depend on drilling fluid for cooling and lubrication during working, and have short service life). One of the main aspects of downhole tool maintenance is the replacement of radial centralizing bearings and axial thrust bearings.

At present, a radial centralizing bearing and an axial thrust bearing of a drilling downhole tool are generally arranged independently, so that the occupied space is large, the axial length of the downhole tool is long, the axial clearance of the bearing is adjusted mainly by experience during maintenance, the clearance adjusting difficulty is high, and time and labor are wasted.

For a well drilling downhole tool, particularly a radial centralizing bearing and an axial thrust bearing of a downhole power drill are independently arranged, and the axial space required for installing the radial centralizing bearing, the axial thrust bearing and a lower radial centralizing bearing is large, so that the distance between an inflection point of a bent shell and the end face of a rotary output shaft (or between the inflection point and a drill bit) is large (generally reaches or exceeds 750 mm-1000 mm). The build rate of the downhole power drill is in inverse proportion to the inflection point distance, so that the build rate of the downhole power drill is low, and the need cannot be met sometimes.

In addition, in other fields, such as an electric submersible pump, a thrust-righting dual-function wear-resistant bearing of the electric submersible pump comprises an upper bearing assembly and a lower bearing assembly; the upper bearing assembly comprises an upper bearing seat and an upper thrust bearing arranged on the upper bearing seat, and the lower bearing assembly comprises a centering bearing inner ring, a centering bearing outer ring and a lower bearing seat which are sequentially arranged on the shaft.

The bearing is a larger complex bearing assembly formed by integrating 2 sets of independent axial thrust rolling bearings and 1 set of radial centering sliding bearings, although the bearing has double functions of axial thrust and radial centering; however, the rated load of the upper thrust bearing and the lower thrust bearing in the bearing assembly is very small (only axial unbalanced force when the submersible electric pump works is needed to be borne), and the rated load of the axial thrust bearing of most downhole tools cannot be achieved (generally more than 100.00 kN). In addition, the cooling and lubricating medium of the bearing assembly is crude oil, and the cooling and lubricating medium cannot be applied to a well drilling downhole tool, because the cooling and lubricating medium of a thrust bearing and a centering bearing in most well drilling downhole tools (particularly turbine drilling tools and screw drilling tools) is drilling fluid (containing barite powder, rock debris particles and the like) with the solid content of 3-5%, and the requirements on the wear resistance and the service life of the bearing are particularly high. In a word, the technology belongs to the field of oil extraction downhole equipment, is not suitable for drilling downhole equipment, and has different working conditions.

Therefore, there is a need for a new sliding bearing assembly with both radial and axial thrust functions to better meet the requirements of modern downhole drilling tools.

It should be noted that the above background description is only for the sake of clarity and complete description of the technical solutions of the present invention, and is set forth for facilitating understanding of those skilled in the art. These solutions are not considered to be known to the person skilled in the art merely because they have been set forth in the background section of the present invention.

SUMMERY OF THE UTILITY MODEL

In order to overcome at least one defect in the prior art, the utility model provides a slide bearing assembly with radial righting and axial thrust functions, which greatly reduces the space required by the installation of the radial righting and axial thrust bearing of the well drilling downhole tool, shortens the axial total length of the downhole tool and improves the build-up rate of the downhole power drilling tool; meanwhile, the concentricity and the working stability of the rotating shaft and the shell of the downhole tool are improved, the vibration frequency and the vibration amplitude of the downhole tool are reduced, the service life of the downhole tool is prolonged, and the comprehensive use requirement of the drilling downhole tool can be met.

In order to achieve the above object, the present invention provides the following technical solutions.

A combination radial centralizing and axial thrust sliding bearing assembly comprising: the static ring comprises a static ring base body in a hollow cylinder shape, wherein the static ring base body is provided with a first inner cylindrical surface and a first outer cylindrical surface which are opposite along the radial direction, and is provided with a first thrust surface and a second thrust surface which are opposite along the axial direction; a first radial friction portion is arranged on the first inner cylindrical surface; at least one of the first thrust surface and the second thrust surface is provided with a first axial friction part; the radial moving ring comprises a hollow cylindrical radial moving ring base body, the radial moving ring base body is provided with a second inner cylindrical surface and a second outer cylindrical surface which are opposite along the radial direction, a second radial friction part is arranged on the second outer cylindrical surface, and a radial friction pair is formed by the first radial friction part and the second radial friction part; the axial rotating ring comprises an annular axial rotating ring base body, the axial rotating ring base body is provided with a third thrust surface and a fourth thrust surface which are opposite along the axial direction, a second axial friction part is arranged on the third thrust surface, the first axial friction part and the second axial friction part form an axial friction pair, and the axial friction pair comprises: any one of polycrystalline diamond friction pairs and PDC composite friction pairs.

In a preferred embodiment, the material of the radial friction pair includes: hard alloy and polycrystalline diamond.

In a preferred embodiment, the sliding bearing assembly is used in a guide short piece in a push-pull type rotary guide system, the number of the axial moving rings is one, the stationary ring and the radial moving ring form a pair of radial centering sliding bearings, and the stationary ring and the axial moving ring form a pair of single axial thrust sliding bearings.

In a preferred embodiment, the sliding bearing assembly is used in a transmission shaft of a downhole power drill, the number of the axial moving rings is two, and the static ring and the radial moving ring form a pair of radial centralizing sliding bearings; the two axial moving rings are respectively arranged on a first thrust surface and a second thrust surface of the static ring and form a double-axial thrust sliding bearing together with the static ring.

In a preferred embodiment, the number of the axial dynamic rings is one, and the static ring includes: the quiet ring of radial righting and the quiet ring of axial thrust that the components of a whole that can function independently set up, slide bearing assembly is arranged in the direction nipple joint among the rotatory guide system of formula of leaning on, radial righting quiet ring includes from inside to outside along radial: the damping ring comprises a first ring body, a damping ring and a second ring body.

In a preferred embodiment, an end face of the first ring body of the radial static ring is in clearance fit with the axial static thrust ring, and an end face of the second ring body of the radial static ring is in contact with an end face of the axial static thrust ring; the other end face of the axial thrust static ring is provided with the first axial friction part; the radial centering static ring and the radial moving ring form a pair of radial centering sliding bearings, and the axial thrust static ring and the axial moving ring form a pair of single-axial thrust sliding bearings.

In a preferred embodiment, one end of the radial rotating ring base body of the radial rotating ring is formed with an extension portion along the radial direction outwards, the extension portion is connected with the axial rotating ring through a connecting piece, and the radial rotating ring and the axial rotating ring jointly form a rotating ring assembly.

In a preferred embodiment, when the axial friction pair and the radial friction pair are polycrystalline diamond friction pairs, a cast tungsten carbide layer is arranged between any one friction part of the polycrystalline diamond friction pair and the corresponding substrate, and the cast tungsten carbide layer and the corresponding substrate are welded together by a welding material through a pressureless dipping sintering method.

In a preferred embodiment, when the axial friction pair is a PDC composite friction pair, any friction part of the PDC composite friction pair is embedded on the base body by gas welding or interference fit.

In a preferred embodiment, when the radial friction pair is a cemented carbide friction pair, a cast tungsten carbide layer is arranged between any friction part of the cemented carbide friction pair and the corresponding substrate, and the cast tungsten carbide layer is welded together by a welding material by a pressureless dip sintering method.

At present, a radial centralizing bearing and an axial thrust bearing of a downhole tool (particularly a downhole power drilling tool) are all independently arranged, and the axial space required for installing the radial centralizing bearing, the axial thrust bearing and a lower radial centralizing bearing is large, so that the distance between an inflection point of a bent shell and the end face of a rotary output shaft (or between the inflection point and a drill bit) is large (generally reaching 750 mm-1000 mm), and the build rate of the downhole power drilling tool is low (the build rate of the downhole power drilling tool is inversely proportional to the distance of the inflection point).

The utility model discloses embodiment provides a have the slide bearing assembly of radial righting and axial thrust effect concurrently, the radial righting bearing that has high wearability is in the same place with axial thrust bearing is integrated completely, and the strong union has greatly reduced the required axial space of installation bearing to reduce the inflection point of curved shell and the axial distance (being less than 750mm) between the rotatory output shaft terminal surface, improved power drilling tool's slope of making in the pit. Furthermore, the utility model discloses the inner cylinder face of quiet ring is mutually perpendicular with terminal surface (first thrust surface and/or second thrust surface), and the quiet ring can receive radial force and axial force effect simultaneously during downhole tool operation, relies on terminal surface pressing mode and cylindric rotating ring and the fixed radial restraint that receives when holistic rotation output shaft is rotatory more just, and the radial slope and the vibration (including vibration frequency and amplitude) of relative quiet circle are littleer, and the concentricity improves.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and the accompanying drawings, which specify the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the present invention are not so limited in scope.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for helping the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. The skilled person in the art can, under the teaching of the present invention, choose various possible shapes and proportional dimensions to implement the invention according to the specific situation. In the drawings:

FIG. 1 is a schematic cross-sectional view of a stationary ring of a sliding bearing assembly having both radial centralizing and single axial thrust;

FIG. 2 is a schematic cross-sectional view of a stationary ring of a sliding bearing assembly having both radial centralization and single axial thrust;

FIG. 3 is a schematic cross-sectional view of a stationary ring of a sliding bearing assembly with both radial centering and biaxial thrust functions;

FIG. 4 is a schematic cross-sectional view of a stationary ring of a sliding bearing assembly with both radial centering and biaxial thrust;

FIG. 5 is a schematic cross-sectional view of a sliding bearing assembly having both radial centralization and single axial thrust;

FIG. 6 is a schematic cross-sectional view of a sliding bearing assembly having both radial centralization and single axial thrust;

FIG. 7 is a schematic cross-sectional view of a sliding bearing assembly having both radial centering and dual axial thrust;

FIG. 8 is a schematic cross-sectional view of a sliding bearing assembly having both radial centering and dual axial thrust;

FIG. 9 is a schematic cross-sectional view of a sliding bearing assembly having both radial centralization and single axial thrust;

FIG. 10 is a cross-sectional view of a sliding bearing assembly having both radial centralization and single axial thrust;

FIG. 11 is a cross-sectional view of a sliding bearing assembly having both radial centralization and single axial thrust;

fig. 12 is a schematic cross-sectional view of a sliding bearing assembly with both radial centralization and single axial thrust.

Description of reference numerals:

1. a stationary ring; 11. a stationary ring base; 111. a static ring is righted in the radial direction; 1111. a first ring body; 1112. a second ring body; 112. an axial thrust static ring; 12. a first radial friction portion; 13. a first inner cylindrical surface; 14. a first axial friction portion; 15. a shock-absorbing ring; 16. a first thrust surface; 17. a second thrust surface; 18. a connecting member;

2. a radial moving ring; 21. a radial rotating ring base; 211. an extension portion; 22. a second radial friction portion; 23. a second outer cylindrical surface;

3. an axial moving ring; 31. an axial rotating ring base; 32. a second axial friction portion;

4. and casting a tungsten carbide layer.

Detailed Description

In order to make the technical solutions in the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 12, the present invention provides a sliding bearing assembly with radial centering and axial thrust functions. The sliding bearing assembly with both radial centralizing and axial thrust functions can comprise: a stationary ring 1, a radially moving ring 2 and at least one axially moving ring 3.

The static ring 1 comprises a static ring base body 11 in a hollow cylindrical shape, wherein the static ring base body 11 is provided with a first inner cylindrical surface 13 and a first outer cylindrical surface which are opposite along the radial direction, and is provided with a first thrust surface 16 and a second thrust surface 17 which are opposite along the axial direction; said first inner cylindrical surface 13 is provided with a first radial friction portion 12; at least one of the first thrust surface 16 and the second thrust surface 17 is provided with a first axial friction portion 14.

The radial moving ring 2 comprises a hollow cylindrical radial moving ring base body 21, the radial moving ring base body 21 is provided with a second inner cylindrical surface and a second outer cylindrical surface 23 which are opposite along the radial direction, and a second radial friction part 22 is arranged on the second outer cylindrical surface 23. The first radial friction part 12 and the second radial friction part 22 form a radial friction pair. The material of the radial friction pair comprises any one of polycrystalline diamond and hard alloy.

The axial moving ring 3 includes an annular axial moving ring base 31, and the axial moving ring base 31 has a third thrust surface and a fourth thrust surface opposite to each other along the axial direction, and the third thrust surface is provided with a second axial friction portion 32. The first axial friction portion 14 and the second axial friction portion 32 form an axial friction pair. The axial friction pair is made of any one of polycrystalline diamond and PDC composite friction part.

Because the strength of the hard alloy is much lower than that of polycrystalline diamond and PDC, the axial length of the radial centralizing bearing can be designed to be very long, the contact area is large, the specific pressure is low, and the hard alloy can completely meet the requirement. Certainly, when the cost is not limited, the material of the radial friction pair is better to select polycrystalline diamond, the service life is longer, but at present, manufacturers or individuals who master the machining process of the polycrystalline diamond radial centering sliding bearing at home and abroad are few, and the machining cost is relatively higher. The contact area of the axial thrust bearing is generally small due to the limitation of the diameter, the contact area is small, the specific pressure is high, and the strength of the hard alloy cannot meet the requirement, so that the high-strength polycrystalline diamond or PDC is selected to form a polycrystalline diamond friction part and a PDC composite friction part, and then a polycrystalline diamond friction pair and a PDC composite friction pair are formed.

Wherein, this PDC composite friction portion specifically can include: the hard alloy wear-resistant layer is provided with a polycrystalline diamond wear-resistant layer with a preset thickness.

In the implementation mode of the application specification, two pairs or three pairs of superhard material friction pairs are arranged in one set of sliding bearing at the same time, so that the inclination angle of the central axis of the rotating shaft relative to the central axis of the stationary shell and the displacement of radial movement are reduced, and the concentricity and the working stability of the rotating shaft and the shell are improved to a certain extent.

On the whole, the sliding bearing assembly with the radial centralizing and axial thrust functions greatly reduces the space required by the installation of the radial centralizing and axial thrust bearing of the well drilling downhole tool, shortens the total length of the downhole tool and improves the build-up rate of the downhole power drilling tool; meanwhile, the concentricity and the working stability of the rotating shaft and the shell of the underground tool are improved, the vibration frequency and the vibration amplitude of the underground tool are reduced, the service life of the underground tool is prolonged, and the comprehensive use requirement of the drilling underground tool can be met.

In the present embodiment, different embodiments will be developed and described in detail mainly depending on the specific composition, structure, and the like of the stationary ring 1.

Referring to fig. 1 and 5, in a first embodiment, a sliding bearing assembly with radial centering and uniaxial thrust functions is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; the disc-shaped axial moving ring 3 and the static ring 1 form a pair of single-axial thrust sliding bearings.

The first axial friction portion 14 of one thrust plane of the stationary ring 1 may be made of polycrystalline diamond. The first radial friction portion 12 provided on the first inner cylindrical surface 13 of the stationary ring 1 may be made of cemented carbide. The first axial friction portion 14 and the first radial friction portion 12 may be welded to the stationary ring base 11 by a pressureless dip sintering method.

The sliding bearing assembly is compact and simple in structure and small in occupied space, is applied to the guide short section in the pushing type rotary guide system, can enable the rotary core shaft to be arranged in the middle, reduces the friction force between the end surface and the inner and outer parts when the rotary core shaft and the lower joint rotate relative to the non-rotary outer barrel, and improves the service life of the guide short section.

Referring to fig. 2 and 6, in a second embodiment, a sliding bearing assembly with radial centering and uniaxial thrust is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; the disc-shaped axial moving ring 3 and the static ring 1 form a pair of single-axial thrust sliding bearings.

The first axial friction part 14 of one thrust plane of the static ring 1 can be made of a PDC composite material, and the first axial friction part 14 can be embedded in a blind hole in the end face of the static ring base body 11 in an interference fit manner; and the material of the first radial friction part 12 on the first inner cylindrical surface 13 of the stationary ring 1 may be polycrystalline diamond, and the first radial friction part 12 may be welded on the first inner cylindrical surface 13 of the stationary ring base body 11 by a pressureless dip sintering method.

The sliding bearing assembly is compact and simple in structure and small in occupied space, is applied to the guide short section in the pushing type rotary guide system, can enable the rotary mandrel to be placed in the middle, greatly reduces the friction force between the end surface and the inner and outer parts when the rotary mandrel and the lower joint rotate relative to the non-rotary outer barrel, and accordingly greatly prolongs the service life of the guide short section.

Referring to fig. 3 and 7, in a third embodiment, a sliding bearing assembly with radial centering and biaxial thrust functions is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; the two disc-shaped axial moving rings 3 are respectively arranged at the first thrust surface 16 and the second thrust surface 17 of the static ring 1, and form a biaxial thrust sliding bearing with the static ring 1.

The material of the first axial friction part 14 on the two thrust surfaces of the static ring 1 may be polycrystalline diamond, and the first axial friction part 14 may be welded on the two thrust surfaces of the static ring base 11 by a pressureless dip sintering method. The material of the first radial friction portion 12 on the first inner cylindrical surface 13 of the stationary ring 1 may be cemented carbide.

The sliding bearing assembly has compact and simple structure and small required space, is applied to a transmission shaft of an underground power drilling tool, can reduce the distance between the inflection point of a bent shell and the end surface (or the inflection point and a drill bit) of a rotating mandrel, and improves the build-up rate and the service life of the underground power drilling tool.

Referring to fig. 4 and 8, in a fourth embodiment, a sliding bearing assembly with radial centering and biaxial thrust functions is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; two disc-shaped movable rings are respectively arranged at a first thrust surface 16 and a second thrust surface 17 of the fixed ring 1, and form a biaxial thrust sliding bearing with the fixed ring 1.

The first axial friction part 14 on the two thrust surfaces of the static ring 1 may be made of a PDC composite material, and the first axial friction part 14 may be embedded in blind holes of the two end surfaces of the static ring base 11 by interference fit. The material of the first radial friction portion 12 on the first inner cylindrical surface 13 of the stationary ring 1 may be polycrystalline diamond, and the first radial friction portion 12 may be welded on the first inner cylindrical surface 13 of the stationary ring base 11 by a pressureless dip sintering method.

Referring to fig. 1 and 9, in a fifth embodiment, a sliding bearing assembly with radial centering and uniaxial thrust is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; a disc-shaped moving ring 3 and a static ring 1 form a pair of single-axial thrust sliding bearings.

The material of the first axial friction portion 14 on the thrust surface of the stationary ring 1 may be polycrystalline diamond, and the material of the first radial friction portion 12 disposed on the first inner cylindrical surface 13 of the stationary ring 1 may be cemented carbide. The first axial friction part 14 and the first radial friction part 12 are welded to the stationary ring base body 11 by a pressureless dip sintering method.

The cylindrical radial moving ring 2 and the disc-shaped axial moving ring 3 are connected together through a connecting piece 18 to form a sliding bearing moving ring assembly. The connecting member 18 may be in the form of a screw, a bolt, a rivet, or the like.

This slide bearing (assembly) compact structure, simple, occupation space is little, is applied to the direction nipple joint among the rotatory guide system of formula of leaning on, can make rotatory dabber placed in the middle, reduces the frictional force between terminal surface and interior spare part when rotatory dabber, lower clutch do not rotate the urceolus relatively, increases rotatory dabber cross sectional area and bending strength to improve the working life of direction nipple joint.

Referring to fig. 2 and 10, in a sixth embodiment, a sliding bearing assembly with radial centering and uniaxial thrust is provided, wherein a cylindrical radial moving ring 2 and a cylindrical static ring 1 form a pair of radial centering sliding bearings; a disc-shaped axial moving ring 3 and a static ring 1 form a pair of single-axial thrust sliding bearings.

The material of the first axial friction part 14 on the thrust surface of the stationary ring 1 may be a PDC composite material. The first axial friction portion 14 may be inserted into a blind hole in the end surface of the stationary ring base 11 by interference fit. The first radial friction portion 12 of the first inner cylindrical surface 13 of the stationary ring 1 may be made of polycrystalline diamond, and the first radial friction portion 12 may be welded to the first inner cylindrical surface 13 of the stationary ring base 11 by a pressureless dip sintering method.

The sliding bearing assembly is compact and simple in structure and small in occupied space, is applied to the guide short section in the pushing type rotary guide system, can enable the rotary mandrel to be placed in the middle, reduces the friction force between the end face and the inner and outer parts when the rotary mandrel and the lower joint rotate relative to the non-rotary outer barrel, increases the cross section area and the bending strength of the rotary mandrel, and greatly prolongs the service life of the guide short section.

Referring to fig. 1 and 11, a seventh embodiment provides a sliding bearing assembly with both radial centralization and single axial thrust. Wherein, this sliding bearing assembly's quiet ring 1 includes: the radial centralizing static ring 111 and the axial thrust static ring 112 are arranged separately. The radial centering static ring 111 is a hollow cylinder, the end surface of the first ring body 1111 is in clearance fit with the axial thrust static ring 112, (i.e. the end surface of the first ring body 1111 does not contact with the axial thrust static ring 112, and the two end surfaces of the first ring body 1111 are free), and one end surface of the second ring body 1112 of the radial centering static ring 111 is in contact with one end surface of the axial thrust static ring 112 (when the end surface of the outer cylinder is assembled, the second ring body 1112 is tightly connected with the axial thrust static ring 112). The other end surface of the axial thrust static ring 112 is provided with the first axial friction portion 14. The radial centering static ring 111 and the cylindrical radial moving ring 2 form a pair of radial centering sliding bearings, and the axial thrust static ring 112 and the axial moving ring 3 form a pair of single-axial thrust sliding bearings.

The material of the first axial friction part 14 disposed on the thrust surface of the static axial thrust ring 112 may be polycrystalline diamond. The first radial friction portion 12 provided on the first inner cylindrical surface 13 of the radial centering ring 111 may be made of cemented carbide. The first axial friction portion 14 and the first radial friction portion 12 may be welded to the stationary ring base 11 by a pressureless dip sintering method.

In this embodiment, a damper ring 15 may be further provided in the radially centering ring 111. Specifically, the radial centering ring 111 may include, from inside to outside in the radial direction: a first ring body 1111, a cushion ring 15, and a second ring body 1112. The damping ring 15 may be made of a fluororubber material. The first ring body 1111, the damper ring 15, the second ring body 1112 and the axial thrust static ring 112 together form a static ring 1 assembly.

In the embodiment, the axial thrust static ring 112 and the radial centering static ring 111 are arranged separately, so that the processing difficulty can be reduced; on the other hand, when the cylindrical radial dynamic ring 2 is subjected to a radial impact force (e.g., when the drill bit cuts the rock in a directional drilling manner), the radial impact force only affects the radial centering static ring 111, but not the axial thrust static ring 112. In particular, when a damper ring (a fluororubber spring) is provided in the radial stabilizer ring 111, the impact force is greatly reduced.

The cylindrical radial moving ring 2 and the disc-shaped axial moving ring 3 are connected together through a connecting piece 18 to form a sliding bearing moving ring assembly. Specifically, one end of the radial moving ring base body 21 of the radial moving ring 2 is formed with an extension portion 211 radially outward, and the extension portion 211 and the axial moving ring 3 are connected together through a connecting member 18 to form a sliding bearing moving ring assembly. The connecting member 18 may be in the form of a screw, a bolt, a rivet, or the like.

The sliding bearing assembly is compact and simple in structure and small in occupied space, is applied to the guide short section in the pushing type rotary guide system, can enable the rotary mandrel to be placed in the middle, reduces the friction force between the end face and the inner and outer parts when the rotary mandrel and the lower joint rotate relative to the non-rotary outer barrel, increases the cross section area and the bending strength of the rotary mandrel, and therefore the service life of the guide short section is prolonged.

Because the damping ring 15 (such as a fluororubber spring) is arranged in the radial centering ring 111, the impact force generated when the guide wing rib (also called a ribbed plate) is contacted with the well wall can be effectively reduced, an MWD probe in a rotary guide system is protected, and favorable conditions are created for accurately measuring the inclination angle and the azimuth angle of the well deviation.

Referring to fig. 2 and 12, an eighth embodiment provides a sliding bearing assembly with both radial centralization and single axial thrust. Wherein, this sliding bearing assembly's quiet ring 1 includes: the radial centralizing static ring 111 and the axial thrust static ring 112 are arranged separately. The radial centering static ring 111 is a hollow cylinder, the end surface of the first ring body 1111 is in clearance fit with the axial thrust static ring 112 (namely, the end surface of the first ring body 1111 does not contact with the axial thrust static ring 112, and the two end surfaces of the first ring body 1111 are free), and the end surface of the second ring body 1112 of the radial centering static ring 111 is in contact with the end surface of the axial thrust static ring 112 (when the end surface of the outer cylinder is assembled, the second ring body 1112 is tightly connected with the axial thrust static ring). The other end surface of the axial thrust static ring 112 is provided with the first axial friction portion 14. The radial centering static ring 111 and the cylindrical radial moving ring 2 form a pair of radial centering sliding bearings, and the axial thrust static ring 112 and the axial moving ring 3 form a pair of single-axial thrust sliding bearings.

The first axial friction part 14 arranged on the thrust surface of the axial thrust static ring 112 may be made of a PDC composite material, and may be embedded in a blind hole in the end surface of the axial thrust static ring 112 in an interference fit manner. The first radial friction portion 12 disposed on the first inner cylindrical surface 13 of the radially centering stationary ring 111 may be made of polycrystalline diamond and welded to the first inner cylindrical surface 13 of the radially centering stationary ring 111 by pressureless dip sintering.

The sliding bearing assembly is compact and simple in structure and small in occupied space, is applied to the guide short section in the pushing type rotary guide system, can enable the rotary mandrel to be placed in the middle, reduces the friction force between the end face and the inner and outer parts when the rotary mandrel and the lower joint rotate relative to the non-rotary outer barrel, increases the dangerous cross-sectional area and the bending strength of the rotary mandrel, and greatly prolongs the service life of the guide short section.

It should be noted that, in the description of the present invention, the terms "first", "second", and the like are used for descriptive purposes only and for distinguishing similar objects, and no order is shown between the two, and no indication or suggestion of relative importance is understood. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The above description is only for the embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention according to the disclosure of the application document.

Claims

1. A sliding bearing assembly having both radial centralizing and axial thrust, comprising: a stationary ring, a radial moving ring and at least one axial moving ring,

the static ring comprises a static ring base body in a hollow cylindrical shape, wherein the static ring base body is provided with a first inner cylindrical surface and a first outer cylindrical surface which are opposite along the radial direction, and is provided with a first thrust surface and a second thrust surface which are opposite along the axial direction; a first radial friction portion is arranged on the first inner cylindrical surface; at least one of the first thrust surface and the second thrust surface is provided with a first axial friction part;

the radial moving ring comprises a hollow cylindrical radial moving ring base body, the radial moving ring base body is provided with a second inner cylindrical surface and a second outer cylindrical surface which are opposite along the radial direction, a second radial friction part is arranged on the second outer cylindrical surface, and a radial friction pair is formed by the first radial friction part and the second radial friction part;

the axial rotating ring comprises an annular axial rotating ring base body, the axial rotating ring base body is provided with a third thrust surface and a fourth thrust surface which are opposite along the axial direction, a second axial friction part is arranged on the third thrust surface, the first axial friction part and the second axial friction part form an axial friction pair, and the axial friction pair comprises: any one of polycrystalline diamond friction pairs and PDC composite friction pairs.

2. A sliding bearing assembly providing both radial righting and axial thrust as claimed in claim 1, wherein said radial friction pair is formed from a material comprising: hard alloy and polycrystalline diamond.

3. The sliding bearing assembly with both radial centering and axial thrust functions of claim 2, wherein the sliding bearing assembly is used in a guide sub of a push-against rotary guide system, the number of the axial moving rings is one, the stationary ring and the radial moving rings form a pair of radial centering sliding bearings, and the stationary ring and one of the axial moving rings form a pair of single axial thrust sliding bearings.

4. The sliding bearing assembly with both radial centralizing and axial thrust functions of claim 2, wherein the sliding bearing assembly is used in a transmission shaft of a downhole power drill, the number of the axial dynamic rings is two, and the static ring and the radial dynamic rings form a pair of radial centralizing sliding bearings; the two axial moving rings are respectively arranged on a first thrust surface and a second thrust surface of the static ring and form a double-axial thrust sliding bearing together with the static ring.

5. The sliding bearing assembly with both radial centering and axial thrust as claimed in claim 2, wherein the number of said axial rotating rings is one, and said stationary ring comprises: the quiet ring of radial righting and the quiet ring of axial thrust that the components of a whole that can function independently set up, slide bearing assembly is arranged in the direction nipple joint among the rotatory guide system of formula of leaning on, radial righting quiet ring includes from inside to outside along radial: the damping ring comprises a first ring body, a damping ring and a second ring body.

6. A sliding bearing assembly having both radial righting and axial thrust as claimed in claim 5, wherein: the end surface of the first ring body of the radial centering static ring is in clearance fit with the axial thrust static ring, and one end surface of the second ring body of the radial centering static ring is in contact with one end surface of the axial thrust static ring; the other end face of the axial thrust static ring is provided with the first axial friction part; the radial centering static ring and the radial moving ring form a pair of radial centering sliding bearings, and the axial thrust static ring and the axial moving ring form a pair of single-axial thrust sliding bearings.

7. A sliding bearing assembly having both radial righting and axial thrust as claimed in claim 6, wherein: one end of a radial moving ring base body of the radial moving ring is formed with an extending portion along the radial direction outwards, the extending portion is connected with the axial moving ring through a connecting piece, and the radial moving ring and the axial moving ring jointly form a moving ring assembly.

8. The sliding bearing assembly with both radial centralizing and axial thrust functions of claim 2, wherein when the axial friction pair and the radial friction pair are polycrystalline diamond friction pairs, a cast tungsten carbide layer is arranged between any friction part of the polycrystalline diamond friction pairs and the corresponding substrate, and the cast tungsten carbide layer is welded together by a welding material by a pressureless dip sintering method.

9. A sliding bearing assembly having both radial righting and axial thrust as claimed in claim 2, wherein: when the axial friction pair is a PDC composite friction pair, any friction part in the PDC composite friction pair is embedded on the base body through protective gas welding or interference fit.

10. A sliding bearing assembly having both radial righting and axial thrust as claimed in claim 2, wherein: when the radial friction pair is a hard alloy friction pair, a cast tungsten carbide layer is arranged between any friction part in the hard alloy friction pair and a corresponding substrate, and the cast tungsten carbide layer is welded together by welding materials by a pressureless dipping sintering method.